Silicon Carbide(SiC) power MOSFETs have the potential to be adopted in high reliability applications, for example automotive, aerospace and military. Estimating or measuring the junction temperature of the power module is an emerging technology for thermal management control, condition monitoring, and lifetime estimation. This paper present a simply thermal model to estimate the junction temperature for SiC modules, which uses integrated negative thermal coefficient(NTC) thermistor. Firstly, a simplified thermal model is established to precisely express the thermal impedance between the chip and the integrated NTC. Then the junction temperature of the module is online estimated based on the obtained thermal model and NTC sensor reading. The effectiveness of the proposed thermal model is verified by simulation and experimental results.